Cappuccino makers known in the art are subject to many limitations. They can be difficult to clean, difficult to use, vulnerable to breakdown and expensive to manufacture. The present invention provides several novel structures and components to address those problems and to provide an improved cappuccino maker.
Cappuccino machines of the prior art typically are difficult to clean and maintain. Because milk products are vulnerable to spoilage and buildup, they must be flushed and cleaned regularly from the internal components of the cappuccino machine. Existing machines require the user to remove and empty the milk receptacle, fill it with water or another cleaning fluid, and run the machine to flush milk residue from the system. This is time-consuming and inconvenient.
U.S. Pat. No. 5,473,972 to Rizzuto et at. (assigned to the assignee of the present invention) discloses a cappuccino maker of this design. It includes a housing, a steam source, coffee maker and coffee dispensing spout, and also discloses as improvements an integral or separate milk frothing unit comprising a venturi, a milk container latchable to the housing, and quick disconnect valves between the venturi and a frothed milk dispensing spout. This construction unit allows the milk container to be separated from the housing for storage in a refrigerator. The Rizzuto et al. patent also discloses quick disconnect valves between a milk delivery tube and the venturi, and a valve in the top of the milk container leading to the milk delivery tube. It further discloses the two dispensing spouts in close proximity, enabling the user to dispense milk and coffee into the same cup without having to move the cup between steps. A conical spring is contained within the venturi to assist in frothing the milk.
In addition to being inconvenient to clean, machines of this design have other limitations addressed by the present invention. Prior art machines having valves at the top of the milk receptacle tend to send a substantial and unmetered amount of air into the frothing device. As the milk is drawn up, the air sitting on the milk's surface is also drawn up through the valve and into the frothing device. This can limit frothed milk production. In addition, prior art machines use complex, user-set air intake valves which are expensive, and subject to breakage and mis-adjustment. The present invention has addressed these problems.